*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --silver-50: #f8f9fa;
  --silver-100: #f1f3f5;
  --silver-200: #e9ecef;
  --silver-300: #dee2e6;
  --silver-400: #ced4da;
  --silver-500: #adb5bd;
  --silver-600: #868e96;
  --silver-700: #495057;
  --silver-800: #343a40;
  --silver-900: #212529;
  --accent: #4a90d9;
  --accent-light: #6ba3e0;
  --green: #2d9a3e;
  --red: #d9534f;
  --bg: #ffffff;
  --surface: #f8f9fa;
  --text: #212529;
  --text-secondary: #6c757d;
  --border: #dee2e6;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 4px 14px rgba(0, 0, 0, 0.1);
}

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--silver-100);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ===== Header / Nav ===== */
.header {
  background: linear-gradient(135deg, var(--silver-800) 0%, var(--silver-700) 100%);
  color: white;
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: relative;
}

.logo { font-size: 1.25rem; font-weight: 700; letter-spacing: -0.02em; color: white; }
.logo:hover { text-decoration: none; }
.logo span { color: var(--silver-400); font-weight: 400; }

.nav-links { display: flex; align-items: center; gap: 0.25rem; }
.nav-links a {
  color: var(--silver-300); padding: 0.4rem 0.85rem; font-size: 0.9rem;
  font-weight: 500; border-radius: 6px; transition: color 0.2s, background 0.2s;
}
.nav-links a:hover, .nav-links a.active {
  color: white; background: rgba(255,255,255,0.1); text-decoration: none;
}

.nav-toggle {
  display: none; background: none; border: none; color: white;
  font-size: 1.5rem; cursor: pointer; padding: 0.25rem; line-height: 1;
}

/* ===== Breadcrumbs ===== */
.breadcrumbs {
  max-width: 1200px; margin: 0 auto; padding: 0.75rem 1.5rem 0;
  font-size: 0.82rem; color: var(--text-secondary);
}
.breadcrumbs a { color: var(--text-secondary); }
.breadcrumbs a:hover { color: var(--accent); }
.breadcrumbs span { margin: 0 0.4rem; color: var(--silver-400); }

/* ===== Container ===== */
.container { max-width: 1200px; margin: 0 auto; padding: 1.5rem; }

/* ===== Contextual Intro ===== */
.contextual-intro {
  background: white; border-radius: var(--radius); padding: 1.75rem 2rem;
  margin-bottom: 1.5rem; box-shadow: var(--shadow); border-left: 4px solid var(--accent);
}
.contextual-intro h1 {
  font-size: 1.5rem; font-weight: 800; color: var(--silver-800);
  margin-bottom: 0.75rem; line-height: 1.3;
}
.contextual-intro p { color: var(--silver-700); line-height: 1.75; margin-bottom: 0.5rem; }

/* ===== Price Hero ===== */
.price-hero {
  background: white; border-radius: var(--radius); padding: 2rem 2.5rem;
  margin-bottom: 1.5rem; box-shadow: var(--shadow); display: flex;
  justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 1.5rem;
}
.price-main { display: flex; flex-direction: column; }
.price-label {
  font-size: 0.85rem; color: var(--text-secondary); text-transform: uppercase;
  letter-spacing: 0.05em; font-weight: 600; margin-bottom: 0.25rem;
}
.price-value { font-size: 3rem; font-weight: 800; letter-spacing: -0.03em; line-height: 1.1; }
.price-change {
  display: inline-flex; align-items: center; gap: 0.35rem; font-size: 1.1rem;
  font-weight: 600; margin-top: 0.5rem; padding: 0.25rem 0.75rem; border-radius: 6px;
}
.price-change.up { color: var(--green); background: rgba(45,154,62,0.08); }
.price-change.down { color: var(--red); background: rgba(217,83,79,0.08); }
.price-change .arrow { font-size: 0.85rem; }
.price-details { display: grid; grid-template-columns: repeat(2,1fr); gap: 0.75rem 2rem; }
.price-detail { display: flex; flex-direction: column; }
.price-detail-label { font-size: 0.75rem; color: var(--text-secondary); text-transform: uppercase; letter-spacing: 0.04em; }
.price-detail-value { font-size: 1.05rem; font-weight: 600; color: var(--silver-800); }
.last-updated { font-size: 0.8rem; color: var(--text-secondary); text-align: right; width: 100%; margin-top: 0.5rem; }

/* ===== Cards ===== */
.card { background: white; border-radius: var(--radius); padding: 1.75rem 2rem; margin-bottom: 1.5rem; box-shadow: var(--shadow); }
.card h2 { font-size: 1.2rem; font-weight: 700; color: var(--silver-800); margin-bottom: 1rem; }

/* ===== Chart ===== */
.chart-controls { display: flex; gap: 0.5rem; margin-bottom: 1rem; flex-wrap: wrap; }
.chart-controls button {
  padding: 0.4rem 1rem; border: 1px solid var(--border); border-radius: 6px;
  background: white; color: var(--text-secondary); font-size: 0.85rem; font-weight: 500;
  cursor: pointer; transition: all 0.2s;
}
.chart-controls button:hover { border-color: var(--accent); color: var(--accent); }
.chart-controls button.active { background: var(--accent); border-color: var(--accent); color: white; }
.chart-wrapper { position: relative; height: 380px; }

/* ===== Stats Grid ===== */
.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px,1fr)); gap: 1rem; }
.stat-card { background: var(--surface); border-radius: 8px; padding: 1.25rem; text-align: center; }
.stat-card .stat-label { font-size: 0.78rem; color: var(--text-secondary); text-transform: uppercase; letter-spacing: 0.04em; margin-bottom: 0.35rem; }
.stat-card .stat-value { font-size: 1.35rem; font-weight: 700; color: var(--silver-800); }
.stat-card .stat-sub { font-size: 0.8rem; color: var(--text-secondary); margin-top: 0.15rem; }

/* ===== Price Table ===== */
.table-wrapper { overflow-x: auto; margin-top: 0.5rem; }
.price-table { width: 100%; border-collapse: collapse; font-size: 0.9rem; }
.price-table th { text-align: left; padding: 0.75rem 1rem; border-bottom: 2px solid var(--border); color: var(--text-secondary); font-weight: 600; font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.03em; white-space: nowrap; }
.price-table td { padding: 0.65rem 1rem; border-bottom: 1px solid var(--silver-200); white-space: nowrap; }
.price-table tr:hover { background: var(--silver-50); }
.price-table .change-up { color: var(--green); }
.price-table .change-down { color: var(--red); }

/* ===== Info Sections ===== */
.info-section h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 0.5rem; color: var(--silver-800); }
.info-section p { margin-bottom: 0.75rem; color: var(--silver-700); line-height: 1.7; }
.info-section ul { margin: 0.5rem 0 1rem 1.25rem; color: var(--silver-700); }
.info-section li { margin-bottom: 0.35rem; line-height: 1.6; }

/* ===== FAQ ===== */
.faq-item { border-bottom: 1px solid var(--silver-200); padding: 1rem 0; }
.faq-item:last-child { border-bottom: none; }
.faq-question { font-weight: 600; cursor: pointer; display: flex; justify-content: space-between; align-items: center; gap: 1rem; color: var(--silver-800); user-select: none; }
.faq-question::after { content: "+"; font-size: 1.2rem; font-weight: 400; color: var(--text-secondary); flex-shrink: 0; transition: transform 0.2s; }
.faq-item.open .faq-question::after { content: "\2212"; }
.faq-answer { display: none; padding-top: 0.75rem; color: var(--silver-700); line-height: 1.7; }
.faq-item.open .faq-answer { display: block; }

/* ===== SEO Section ===== */
.seo-section { background: var(--silver-50); border-radius: var(--radius); padding: 2rem 2.5rem; margin-bottom: 1.5rem; }
.seo-section h2 { font-size: 1.15rem; font-weight: 700; color: var(--silver-800); margin-bottom: 0.75rem; }
.seo-section p { color: var(--silver-600); font-size: 0.92rem; line-height: 1.8; margin-bottom: 0.6rem; }

/* ===== Latest Articles ===== */
.latest-articles { background: white; border-radius: var(--radius); padding: 1.75rem 2rem; margin-bottom: 1.5rem; box-shadow: var(--shadow); }
.latest-articles h2 { font-size: 1.2rem; font-weight: 700; color: var(--silver-800); margin-bottom: 1rem; }
.articles-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px,1fr)); gap: 1.25rem; }
.article-card { display: block; border: 1px solid var(--silver-200); border-radius: 8px; padding: 1.25rem; transition: box-shadow 0.2s, border-color 0.2s; color: inherit; }
.article-card:hover { box-shadow: var(--shadow-lg); border-color: var(--accent); text-decoration: none; }
.article-card .article-date { font-size: 0.78rem; color: var(--text-secondary); margin-bottom: 0.35rem; }
.article-card .article-title { font-size: 1rem; font-weight: 600; color: var(--silver-800); margin-bottom: 0.5rem; line-height: 1.4; }
.article-card .article-excerpt { font-size: 0.88rem; color: var(--silver-600); line-height: 1.5; }
.articles-view-all { display: inline-block; margin-top: 1rem; font-weight: 600; font-size: 0.9rem; }

/* ===== Blog Index ===== */
.blog-list { list-style: none; }
.blog-list li { background: white; border-radius: 8px; margin-bottom: 1rem; box-shadow: var(--shadow); transition: box-shadow 0.2s; }
.blog-list li:hover { box-shadow: var(--shadow-lg); }
.blog-list a { display: block; padding: 1.25rem 1.5rem; color: inherit; }
.blog-list a:hover { text-decoration: none; }
.blog-list .blog-date { font-size: 0.8rem; color: var(--text-secondary); margin-bottom: 0.25rem; }
.blog-list .blog-title { font-size: 1.1rem; font-weight: 700; color: var(--silver-800); margin-bottom: 0.35rem; }
.blog-list .blog-excerpt { font-size: 0.9rem; color: var(--silver-600); line-height: 1.5; }

/* ===== Blog Post / Article Content ===== */
.article-content { background: white; border-radius: var(--radius); padding: 2.5rem 3rem; margin-bottom: 1.5rem; box-shadow: var(--shadow); }
.article-content h1 { font-size: 1.75rem; font-weight: 800; color: var(--silver-900); margin-bottom: 0.5rem; line-height: 1.3; }
.article-meta { font-size: 0.85rem; color: var(--text-secondary); margin-bottom: 1.5rem; padding-bottom: 1rem; border-bottom: 1px solid var(--silver-200); }
.article-content h2 { font-size: 1.3rem; font-weight: 700; color: var(--silver-800); margin: 1.75rem 0 0.75rem; }
.article-content p { margin-bottom: 1rem; color: var(--silver-700); line-height: 1.8; }
.article-content ul, .article-content ol { margin: 0.5rem 0 1rem 1.5rem; color: var(--silver-700); line-height: 1.7; }
.article-content li { margin-bottom: 0.4rem; }
.article-cta { background: var(--silver-50); border: 1px solid var(--silver-200); border-radius: 8px; padding: 1.25rem 1.5rem; margin: 1.5rem 0; text-align: center; }
.article-cta a { font-weight: 600; }

/* ===== Legal / Static Pages ===== */
.page-content { background: white; border-radius: var(--radius); padding: 2.5rem 3rem; margin-bottom: 1.5rem; box-shadow: var(--shadow); }
.page-content h1 { font-size: 1.75rem; font-weight: 800; color: var(--silver-900); margin-bottom: 1.25rem; }
.page-content h2 { font-size: 1.2rem; font-weight: 700; color: var(--silver-800); margin: 1.5rem 0 0.5rem; }
.page-content p { margin-bottom: 0.75rem; color: var(--silver-700); line-height: 1.7; }
.page-content ul { margin: 0.5rem 0 1rem 1.5rem; color: var(--silver-700); }
.page-content li { margin-bottom: 0.35rem; line-height: 1.6; }

/* ===== Footer ===== */
.footer { background: var(--silver-800); color: var(--silver-400); padding: 2.5rem 0 1.5rem; margin-top: 1rem; }
.footer-inner { max-width: 1200px; margin: 0 auto; padding: 0 1.5rem; }
.footer-top { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 2rem; margin-bottom: 1.5rem; }
.footer-brand p { font-size: 0.85rem; line-height: 1.6; margin-top: 0.5rem; }
.footer-nav h4, .footer-legal h4 { color: var(--silver-200); font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: 0.75rem; }
.footer-nav a, .footer-legal a { display: block; color: var(--silver-400); font-size: 0.85rem; padding: 0.2rem 0; }
.footer-nav a:hover, .footer-legal a:hover { color: white; text-decoration: none; }
.footer-bottom { border-top: 1px solid var(--silver-700); padding-top: 1rem; display: flex; justify-content: space-between; align-items: flex-start; flex-wrap: wrap; gap: 1rem; }
.footer-bottom p { font-size: 0.8rem; }
.disclaimer { font-size: 0.78rem; color: var(--silver-500); line-height: 1.5; max-width: 800px; }

/* ===== Loading ===== */
.loading { text-align: center; padding: 3rem; color: var(--text-secondary); }
.loading-spinner { width: 32px; height: 32px; border: 3px solid var(--silver-300); border-top-color: var(--accent); border-radius: 50%; animation: spin 0.8s linear infinite; margin: 0 auto 1rem; }
@keyframes spin { to { transform: rotate(360deg); } }

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .nav-toggle { display: block; }
  .nav-links { display: none; position: absolute; top: 100%; left: 0; right: 0; background: var(--silver-800); flex-direction: column; padding: 0.5rem 1.5rem 1rem; gap: 0; box-shadow: 0 4px 12px rgba(0,0,0,0.2); }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 0.6rem 0; border-radius: 0; }
  .price-hero { padding: 1.5rem; flex-direction: column; align-items: flex-start; }
  .price-value { font-size: 2.2rem; }
  .price-details { width: 100%; }
  .chart-wrapper { height: 280px; }
  .stats-grid { grid-template-columns: repeat(2,1fr); }
  .card { padding: 1.25rem; }
  .seo-section { padding: 1.5rem; }
  .article-content { padding: 1.5rem; }
  .page-content { padding: 1.5rem; }
  .footer-top { grid-template-columns: 1fr; gap: 1.5rem; }
  .articles-grid { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  .stats-grid { grid-template-columns: 1fr; }
  .price-details { grid-template-columns: 1fr; }
  .contextual-intro h1 { font-size: 1.25rem; }
}